1. Field of the Invention
The present general inventive concept relates to a toner, a method of preparing the toner, a method of forming images using the toner and an image forming device using the toner, and more particularly, to a toner having improved fixing and charging properties, preserving properties at a high temperature and high humidity, glossness and anti-offset properties by reducing a domain size of a wax dispersed in the toner and improving dispersity of the wax, a method of preparing the toner, a method of forming images using the toner and an image forming device using the toner.
2. Description of the Related Art
In electrophotographic processes or electrostatic recording processes, a developer used to develop an electrostatic image or an electrostatic latent image is classified into a two-component developer formed of toner and carrier particles, and a one-component developer formed of toner only. The one-component developer is classified into a magnetic one-component developer and a nonmagnetic one-component developer. Fluiding agents such as colloidal silica are often independently added to the nonmagnetic one-component developer to increase the fluidity of the toner. Typically, coloring particles obtained by dispersing a pigment such as carbon black, or other additives in a binding resin are used as the toner.
Toner can be prepared by pulverization or polymerization. In pulverization, toner is obtained by melting and mixing synthetic resins with pigments and, if required, other additives, pulverizing the mixture and sorting the particles until particles of a desired size are obtained. In polymerization, a polymerizable monomer composition is manufactured by uniformly dissolving or dispersing various additives such as a pigment, a polymerization initiator and, if required, a cross-linking agent and an antistatic agent in a polymerizable monomer. Then, the polymerizable monomer composition is dispersed in an aqueous dispersive medium which includes a dispersion stabilizer using an agitator to shape minute liquid droplet particles. Subsequently, the temperature is increased and suspension polymerization is performed to obtain polymerized toner having coloring polymer particles of a desired size.
In an image forming device such as an electrophotographic apparatus or an electrostatic recording apparatus, an image is formed by exposing an image on a uniformly charged photoreceptor to form an electrostatic latent image; attaching toner to the electrostatic latent image to form a toner image; transferring the toner image onto a transfer member such as transfer paper or the like; and then fixing the toner image on the transfer member by any of a variety of methods, including heating, pressurizing, solvent steaming and the like. In most fixing processes, the transfer medium with the toner image passes through fixing rollers and pressing rollers, and by heating and pressing, the toner image is fused to the transfer medium.
Images formed by an image forming device such as an electrophotocopier should satisfy requirements of high precision and accuracy. Conventionally, toner used in an image forming device is usually obtained using pulverization. In pulverization, color particles having a large range of sizes are formed. Hence, to obtain satisfactory developing properties, there is a need to sort the coloring particles obtained through pulverization according to size to reduce particle size distribution. However, precisely controlling the particle size and the particle size distribution using a conventional mixing/pulverizing process in the manufacture of toner suitable for an electrophotographic process or an electrostatic recording process is difficult. Also, when preparing a fine-particle toner, the toner preparation yield is adversely affected by the sorting process. In addition, there are limits to change/adjustment of a toner design for obtaining desirable charging and fixing properties. Accordingly, polymerized toner and the size of particles of which is easy to control and which do not need to undergo a complex manufacturing process such as sorting, have been highlighted recently as disclosed in, for example, U.S. Pat. No. 6,617,091.
However, a wax included in a toner may be plasticized due to comparability of the wax with a resin of the toner according to the conventional art, and thus heat preserving properties, fluidity and fixing properties of the toner may be reduced. Those problems may be overcome according to the present general inventive concept.